1. Technical Field
The present invention relates to a manufacturing method of a liquid ejecting head which ejects liquid from nozzle openings, particularly a manufacturing method of an ink jet type recording head which discharges ink as liquid.
2. Related Art
There is a known ink jet type recording head which is the liquid ejecting head including a flow path formation substrate in which a pressure generation chamber communicating with nozzle openings is formed, a piezoelectric actuator which is provided on one surface side of the flow path formation substrate, and a protection substrate which is bonded to the flow path formation substrate on the piezoelectric actuator side.
In addition, such an ink jet type recording head is manufactured by forming the piezoelectric actuator on the flow path formation substrate which is formed of a silicon single-crystal substrate, then bonding the protection substrate to the upper portion thereof, and then, in a state where a surface of the protection substrate which is on the opposite surface side to the flow path formation substrate is covered and protected by a sealing sheet, performing wet etching of the flow path formation substrate with an etching solution formed of an alkaline aqueous solution such as KOH to form the pressure generation chamber and the like (for example, see Japanese Patent No. 4798348).
However, if the wet etching of the flow path formation substrate which is formed of a silicon single-crystal substrate is performed with the etching solution formed of an alkaline aqueous solution such as potassium hydroxide (KOH), hydrogen gas is generated and damages a piezoelectric layer so that a piezoelectric property of the piezoelectric layer is decreased.
Such a problem does not only occur in the manufacturing method of the ink jet type recording head, but also occurs in a manufacturing method of a liquid ejecting head which ejects liquid other than ink.